Okay Trigeminal Neuralgia is the name of the facial nerve pain associated with MS. It can be triggered by MS and tooth can be treated/pulled in an effort to determine source of pain - incorrectly, or it can be pain as a result of dental work / infection that does not stop when work is completed.
When properly diagnosed there are medicinal and natural remedies recommended. Just a possibility, good luck!
Please research facial nerve damage. If I am not mistaken, there is a nerve series that runs on the side of the face from approx. the temple to the jaw bone that can become inflamed with dental work/infection, and for reasons unknown. I believe this is seen more often in people with MS. There have been treatments successful in relieving the pain. I cannot recall the name of this pain as the word is a little lengthy. You really should not have to live with pain.
Perhaps Google, facial nerve pain or dental, facial pain. More on this if I come accross the name in my searches...
Seeing your surgeon is advised.